User terminal, radio base station, radio communication system, and radio communication method

Abstract

In order to change PUCCH transmission cells appropriately, the present invention provides a user terminal that communicates with a plurality of cell groups each consisting of one or more cells using different frequency bands, the user terminal comprising: a reception section that receives a radio resource control (RRC) message; and a control section that selects at least one cell from cells that are configured for each of the cell groups and are allocatable with an uplink control signal, and controls the cell to be a cell for transmitting the uplink control signal, wherein when the RRC message includes a change instruction of the cell allocatable with the uplink control signal, the control section controls to transmit transmission acknowledgement information (HARQ-ACK) in response to the RRC message in the cell before change.

The invention claimed is: 
     
       1. A user terminal that communicates with use of a plurality of physical uplink control channel (PUCCH) cells, the user terminal comprising:
 a receiver that receives a radio resource control (RRC) message including a PUCCH secondary cell (SCell) change instruction which includes information on a changed scheduling request (SR) report resource after the PUCCH SCell change; 
 a processor that changes at least one PUCCH SCell based on the RRC message; and 
 a transmitter that transmits transmission acknowledgement information (HARQ-ACK: Hybrid Automatic Repeat reQuest-ACKnowledgement) in response to the RRC message by using a PUCCH transmission setting before the PUCCH SCell change, 
 wherein after receiving the RRC message, the processor stops SR transmission in a PUCCH SCell before the PUCCH SCell change. 
 
     
     
       2. The user terminal according to  claim 1 , wherein when the user terminal communicates using dual connectivity, the receiver receives the RRC message in a cell belonging to a master cell group, and the transmitter transmits the HARQ-ACK for the RRC message in a primary cell (PCell). 
     
     
       3. The user terminal according to  claim 1 , wherein when the user terminal communicates using carrier aggregation, the receiver receives the RRC message in any cell and the transmitter transmits the HARQ-ACK for the RRC message in the PUCCH SCell before the PUCCH SCell change. 
     
     
       4. A radio communication method for a user terminal communicating with use of a plurality of physical uplink control channel (PUCCH) cells, the radio communication method comprising:
 receiving a radio resource control (RRC) message including a PUCCH secondary cell (SCell) change instruction which includes information on a changed scheduling request (SR) report resource after the PUCCH SCell change; 
 changing at least one PUCCH SCell based on the RRC message; and 
 transmitting transmission acknowledgement information (HARQ-ACK: Hybrid Automatic Repeat reQuest-ACKnowledgement) in response to the RRC message by using a PUCCH transmission setting before the PUCCH SCell change, 
 wherein after receiving the RRC message, the processor stops SR transmission in a PUCCH SCell before the PUCCH SCell change.